Found in a documentation for radio amateurs from the 90s, this circuit is suitable for RF measurements in transmission systems. The potentiometer must be of a special type.
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...
Lockout shooting, due to the incidence of light, can be achieved with the circuit in the figure. In...
This circuit can function either as a crystal or galena receiver with a pre-amplifier using a FET...